Paper.



"UNIT D STATES PATENT orrron KNIGHT E. ROGERS, OF SOUTH MANCHESTER, CONNECTICUT.

rAPER.

No Drawing.

Specification of Letters Patent. Patented Apr. 11, 1911 Application filed January 28, 1910. Serial No. 540,640.

view, viz., the production of paper possessing the maximum amount of pliability or flexibility and also possessing a satin-like and smooth surface finish. Paper possessing r these characteristics is particularly useful in many difierent connections for example in the textile art and also in the electrical art. Paper having a high surface polish presents unusual dielectric strength and owing to the flexible nature of the article to which I have alluded, the material can be curved and bent in commutator construction, for example, without possibility of its breaking, this being due to the fact that the paper is impregnated with or permeated by a suitable lubricant and the pulp from which the paper is made can vary greatly and the same remark applies to the lubricant. I find that I can secure excellent results with a pulp made from rags'and rag-shavings while the lubricant consists of a soluble, fatty acid soap for example as what is known in 'commerce as neutral chips. The proportions of these ingredients when I use them, may

- vary considerably although I will hereinafter describe a satisfactory mixture solely to comply with the statute or to enable those skilled in the paper art to practice the'in-' vention.

In practicing my method I make paper precisely similar to' any one of the common methodsnowin vogue one of which I might set forth somewhat in-detail, the same being as followsz. After cotton rags have been cleaned they with tag shavings are introduced into a beating engine with water and there macerated to produce a pulp. Whenthe pulp is of the desired fineness or grade it is dropped into the stuff-chest of a 'paper machine where it is formed into a web or fiieets, said web or sheets being dried and nally calendered. Paper made in accordance with this and other existing methods cannot be Friction-finished and to secure such an article I incorporate in the pulp material at some point before it is dried or when the same is in a substantially wet or semi-plastic condition, a suitable lubricant and there are of course, many lubricants which I might employ. I have obtained excellent results by adding the lubricant to the pulp material while the latter is in the beating engine as in this way I can utilize the said engine for securing a mostthorough association of the ingredients or the permeation of the lubricant into every part of the pul lp mass. It is conceivable of course that might mix the lubricant with the paper pulp material before the same is put in the beating engine or while said material in its raw or cru'de state. The proportions of the pulp and lubricant may vary considerably. I get a good mixture by using about ten pounds of the lubricant to about five hundred pounds of-the pulp, the lubricant being introduced into the beating engine prior to the discharge of' the pulp therefrom into the stuff chest. I may as an illustration subject the pulp to the operation of the beating engine.

for approximately ten hours and when the lubricant is put into the beating engine the two ingredients can be subjected to the action of said engine for about half an hour which I find assures a thorough amalgamation of the same. It will, therefore, be apparent that I employ about 2% of the soap lubricant to the pulp or other paper mav already indicated. As will be inferred from what I have already stated there are other satisfactory lubricants; for example any of the saponifying oils to which I .can add sufficient alkali to saponif the same. But I have obtained excellent e ects from the soap mixture which presents a suitable form of lubricant having an afiinity for water.

The lubricated, dried sheet is rendered exceedingly susceptible to friction finishing an operation whichinvolves the application of pressure to and friction upon the lubricant-impregnated sheet although there may be cases where I should simply calender such a sheet. 1 A friction-finished sheet, however ,'as will be understood possesses unusual surface smoothness and polish, and fits the same especially to the uses to which I have referred. There are various ways in which I can obtain the requisite friction finish although a sheet-supporting bed plateand a cooperating ironing or polishing member constitutes an advantageous means for this purpose. The bed-plate when employed will. be so mounted as to withstand the great pressure of and friction produced by the friction-finishing member. The latter may consistof a metallic body having a polishing surface, the sheets to be frictionfinished being laid upon the bed-plate and being traversed by the polishing surface of the friction-finishing member w ich may be supported over the bed-plate in any desir- 4 able manner and be reciprocated or oscillated in any convenient way. The pressure developed by such a member is considerable although it will vary with the grade of the paper. As an illustration I would apply to a comparatively thin board or paper a pressure of substantially five thousand pounds to the square inch. When the sheet is impregnated with the lubricant I find that there is no tendency of the polishing member disturbing the fibers-"of the paper but on the contrary this actually tends to increase the lay of the fibers and addyto .of manufacture to be made up by them into the finished article.

What I claim is:

1. Paper impregnated with a lubricant consisting of a soluble, fatty acid soap, there being about 2% of said lubricant to the paper materia 2. Paper impregnated with a lubricant,

there being not over 5% of said lubricant to the paper material, said lubricant'consisting of a soluble, fatty acid soap.

3. Paper impregnated with a lubricant consisting of a soluble fatty acid soap having a friction finished surface. p

4. Paper impregnated with a lubricant, there being not more than 5% of lubricant to the paper material, said lubricant consisting of a. soluble fat-tyacid soap and the paper having a friction finished surface.

I In testimony whereof I aflix my signature in presence of two witnesses.

' KNIGHT E. ROGERS.

Witnesses:

HEATH sUTI-IERLAND, F. E. ANDERSON. 

